Channel construction for comminutors



A. C. DURDIN, JR

CHANNEL CONSTRUCTION FOR COMMINUTORS Filed March 10, 1939 May 13, 1941.

INVENTOR. Mayan/a1 C flurd/h /n the cutting bar Patented May 13, 1941 UNITED STAT CHANNEL CONSTRUCTION FOB COMMINUTOBS' Augustus O.

or to Chicago Durdin, Jr.,

Pump Company,

corporation of Illinois Application March 10, 1939, Serial No. 261,006

8 Claim.

This invention relates to channel construction for comminutors of that type of comminutors which is placed in a flowing stream of liquids containing solids and semi-solids, as, for in- 7 ing accompanying to pass through the comminutor, and act to reduce the intercepted solids into pieces small enough to pass through the comminutor along with the flowing stream of liquid. Some comminutors employ a rotating straining element having cutting teeth thereon which cooperate with a stationary notched cutting bar to comminute the solids and semi-solids, and when the transverse cutting axis of the comminutor is disposed in a plane at right angles to the longitudinal axis of the channel, the solids and semisolids collect on the cutting bar and interfere with the efliciency of the comminutor because the teeth of the rotating element are likely to merely cut grooves through the solids and semisolids collected on the notched cutting bar instead of attacking different places on the solids and semi-solids.

In order to obtain ing action, the solids and semi-solids should be prevented from lodging on and clinging to the the most efllcient comminut cutting bar because by c ntinuously presenting diflerent parts of solids and semi-solids to the cutting teeth of the rotating element, they are more quickly reduced to small enough pieces to pass through the comminutor.

In accordance with the present invention, the transverse cutting axis of the comminutor is positioned to extend in a direction along the flow of the stream, more or less, so that the flowing liquids may wash the solids and semi-solids from the cutting bar and to facilitate this, the side wall of the channel opposite the one at which is positioned is shaped to direct the stream towards the side of the rotating comminuting element opposite the one where the cutting bar is located. The pressure-of the flowing stream acts to hold solids and semi-solids against the cylindrical face of the rotating element, whereby they are thereby carried to the cutting bar so as to permit the teeth on the rotating element to cut or shear of! small pieces as the teeth pass through the notches of the cutting bar. The invention consists, therefore, in the several novel features hereinafter fully set forth and claimed.

Lincolnwood, Ill., assign- Chicago, 111., a

The invention is clearly illustrated in the drawthis specification, in which:

Fig. l is a plan of a portion of a channel with a comminutor disposed therein and illustrating one form of the present invention.

Fig. 2 is a vertical cross-section taken on the broken line 2-2 of Fig. 1.

Fig. 3 is a perspective view of an enlarged scale of fragments of the rotating cutting element and the notched cutting bar of the comminutor.

Fig. 4 is a plan illustrating a modified form of the invention; and

Fig. 5 is a plan of a second modification.

Referring to said drawing, and flrst to Figs. 1 to 3 inclusive, the reference'character Ill designates a channel usually formed of concrete and comprising side walls II, I! and a bottom II. A stream of sewage or other liquids containin solids and semi-solids flows through the channel in the general direction of the arrow a. when used in sewage treatment plants, the upstream end 22, of the channel may be connected with the outlet of a sewer pipe and the downstream end c may run to a tank or other reservoir for conveying the sewage thereto for subsequent treatment.

Interposed in the channel is a comminutor i4 desirably of the type in which the liquids flow through the slots of a rotating, transversely slotted comminuting element l5, and the solids and semi-solids are detained or intercepted on the surface of the rotating element and reduced to pieces small enough to pass through the slots of the rotating comminuting element or at least reduced to such small pieces as not to interfere For the purpose of illustration, the rotating comminuting element is of cylindrical form composed of spaced discs I. mounted on a shaft 30, which discs provide narrow transverse slots therebetween, the discs being provided with cutting teeth l1 on their peripheral edges which cooperate with a notched cutting bar minutor and may be stationarlly mounted on the wall ll of the channel. Desirably, a pilaster it, which forms part of the commlnutor; is fastened to the channel wall H, and the notched cutting bar is bolted or otherwise secured to the pilaster. The notches are so located on the cutting bar that the cutting teeth llpass through them and shear, cut or tear the solids and semi-solids and reduce them to pieces small enough to pass through the slots or passages in the rotating comminutor element, or atleast reduce them to such small enough pieces thatare not objection- I8 which comprises part of the com-' able to further treatment of the sewage in the plant. The normal transverse or cutting axis of the comminutor is shown as disposed at an angle of about forty-five degrees to the longitudinal axis of the channel, although that angle may be an oblique face aligned with the oblique face of the cutting bar as shown whereby liquid flowing through the channel adjacent the Wall ll washes away solids and semi-solids that would otherwise collect and cling to the cutting bar. Solids and semi-solids are pressed against the face of the rotating element of the comminutor by the flowing stream and are carriedback to the cutting bar by the rotating element, thus enabling the cutting teeth to attaclg other places on the solids and semi-solids.

For the purpose of setting up the desired direction of flow of the stream, the wall adjacent the comminutor on the up-stream side thereof is given a. shape to attain this end. As shown,

an abutment 2! extends from the wall l2 toward the middle of the channel, which abutment has two oblique faces 22, 23, that taper towards each 0ther-from the wall to an apex 24. The tapered face 23 merges into an outwardly curved or concave face 25, which desirably extends part way around the comminutor. The walls 22, 23 and serve to direct the flow of the stream towards the side of the comminutor which is adjacent the wall 12 so that the flow of the liquids along the wall ll sets up-eddy currents at the oblique faces of the pilaster and cutting bar and washaway solids and semi-so ids which would otherwise be likely to collect thereon and cling thereto.

A pilaster 26 may be fastened to the wall l2 of the channel at the side of the comminutor the walls ll I2 diametrically opposite the one Where the cutting bar is positioned, and serves to prevent solid matter from passing between the comminutor and wall l2 to the downstream side of the channel.

Supported by the pilasters is a table 28, upon which is mounted a motor 29, the shaft of which is connected to the shaft 30 of the comminutor.

In the operation of the apparatus the motor drives the rotating element of the comminutor in the direction of the arrow thereon in Fig. 1 and the cutting teeth I! shear, cut or tear solids or semi-solids as the teeth pass through the notches in the cutting bar i8. Material intercepted by the cylindrical face of the rotating comminutor element is carried thereby to the cutting bar and small pieces are cut out of it as the cutting teeth pass through the notches of the bar. The flowing stream, being directed as above set forth, the solids and semi-solids are not permitted to collect upon the cutting bar but are washed away therefrom to be subsequently carried thereto by the rotating comminuting element.

The form of the invention illustrated in Fig. 1 may be readily adapted to present channels by changing the shape of one of the side walls as above suggested, and by placing the transverse cutting axis of the comminutor at-an angle to the longitudinal axis of the channel except at a right angle or nearly a right angle thereto. 7

In the modified form of the invention illustrated in Fig. 4, the side walls Il I2, of the conduit are widened slightly at places adjacent the comminutor as seen at- I I I2", and the inner face of the wall l2 is given the same general shape as that of the corresponding face of the preferred form. If desired, the wall ll" may be formed with an inclined face ll which coincides with the normal or transverse cutting axis of the comminutor I4 The comminutor may be constructed substantially in accordance with the one illustrated in Figs. 1, 2 and 3, and the notched cutting bar I8 is set'at substantially the same angle as the oblique face H of the channel wall I l A pilaster or other bar 26 is provided between the end of the concave face of the wall 12 and the rotating comminutor element. This form of the invention is intended where it is desirable to set the transverse cutting axis at a more acute angle with respect to the longitudinal axis of the channel, said' angle being here shown as one approximately thirty degrees to the longitudinal axis of the channel.

In the. form of the invention illustrated in Fig. 5, the upstream end b of the channel is offset laterally with respect to the downstream end 0, thereof, and the comminutor M is disposed in the transverse portion which joins the offset parts of the channel. In this case the abutments or oblique faces of the channel walls of the other forms may be dispensed with but the curved faces 25 may run from the side walls I I IT, to In this case, the transverse cutting axis of the comminutor is parallel with the longitudinal axes of the channel sections with the cutting bar ltl disposed along the inner face of the wall H A pilaster or other bar 26 may be fastened to the wall l2 and may extend to the rotating comminutor element whereby to prevent solids from passing through the gap between the comminutor and curved face 25*.

In the modified forms of the invention shown in Figs. 4 and 5, the flowing stream also washes any solids or semi-solids away from the cutting bar which otherwise would be likely to collect thereon and cling thereto.

I claim. as new and desire to secure by Letters Patent:

1. The combination of a channel, through which flows a stream of liquid containing solids and semi-solids, a combined comminutor and strainer having a cutting bar disposed on the upstream side of the combined comminutor and strainer, the latter being interposed in said channel with its transverse cutting axis disposed at less than a right angle to the longitudinal axis of the channel, and means to direct the flow of the entire stream transversely through the straining element of the combined comminutor and strainer.

2. The combination of a channel, through which flows a stream of liquid containing solids and semi-solids, a combined comminutor and strainer having a cutting bar disposed on the upstream side of the combined comminutor and strainer, the latter being interposed in said channel with its transverse cutting axis disposed at an angle of forty-five degrees or less to the longitudinal axis of the channel, and means to direct the flow of the entire stream transversely through the straining element of the combined comminutor and strainer.

3. The combination of a channel. through which flows a stream of liquid containing solids and semi-solids. a combined comminutor and strainer having a rotating element and a stationary cutting bar cooperating therewith. said combined comminutor and strainer being interposed in said channel with its transverse cutting containing solids and axis disposed at less than a right angle to the longitudinal axis of the channel, the side wall of the latter opposite the cutting bar of the comminutor having :a flow directing face extending obliquely towards the middle of the nnel on the upstream side of and at a place a jacent the comminutor, and a concave flow directing face extending from the end of said oblique face part way around the comminutor, and a wall closing the gap through the concave face and comminutor.

4. The combination of a channel, through which flows a stream of liquid containing solids and semi-solids, a combined comminutor and strainer having a rotating element and a stationary cutting bar cooperating therewith, said combined comminutor and strainer being interposed in said channel with its transverse cutting axis disposed at less than a right angle to the longitudinal axis of the channel, a flow directing faceat one channel wall flush with'the cutting bar of the comminutor, and a tapered abutment extending from the other wall toward the middle of the channel, on the upstream side of the comminutor, one face of said abutment merging into a concave face extending part way around the comminutor, and a wall to close the gap between said curved iace and-the comminutor.

5. Sewage comminuting apparatus comprising a channel, through which flows a stream of liquid semi-solids, a rotating, radially slotted, comminuting element having cutting teeth on its face and interposed in the stream, a. stationary notched cutting bar cooperating with said cutting teeth to comminute solids and semi-solids carried by the stream, said cutting bar being disposed at an angle oblique to the longitudinal axis of the channel and interposed between the rotating comminuting element and the adjacent side wall of the channel, a bar supporting element closing the gap between the rotating comminuting element and the adjacent side wall, the opposite side wall of the channel having a flow directing abutment extending toward the middle of the channel, and continuing in a receding concave face extending from. the abutment part way around the rotating comminuting element, and a wall closing the gap between said concave wall and rotating comminuting element.

6. Comminuting apparatus comprising a channel, through which flows a stream of liquid containing solids and semi-solids, comminuting means comprising a rotating, radially slotted, comminuting element having cutting teeth on its cylindrical face and a notched cutting bar cooperating with said cutting teeth to comminute solids and semi-solids contained in the flowin stream, said comminuting means being located in the channel with the cutting bar disposed approximately parallel with the longitudinal axis of the channel, whereby solids and semi-solids are washed along the cutting bar towards the rotating comminuting element, the wall on the opposite side of the channel being formed with an abutment projecting towards the middle or the channel, and said abutment terminating in a concave face partly surrounding the rotating comminuting element, and a wall closing the gap between the concave wall and rotating comminuting element.

7. comminuting apparatus comprising a channel, through which flows a stream of liquid containing solids and semi-solids, comminuting means comprising a rotating, radially slotted, comminuting element having cutting teeth on its cylindrical face, a notched cutting bar cooperating with said cutting teeth to comminute solids and semi-solids, and bar supporting means, said comminuting means being located in the channel with the cutting bar disposed at less than a right angle with respect to the longitudinal axis of the channel and there being a wall substantially flush with the cutting bar and extending therefrom to the adjacent side wall of the channel, whereby solids and semi-solids are washed from the cutting bar by the flowing stream, the face of the side wall of the channel opposite the one at which the cutting bar is positioned being offset towards the middle of the channel with one part extending part way around I the rotating comminuting element, and a wall closing the gap between said side wall and rotating comminuting element.

8. The com ination of a channel, through which flows a stream of liquids containing solids and semi-solids, said channel having a laterally offset part, a combined comminutor and strainer interposed in the channel at the oifset part thereof, and having its transverse cutting axis ar ranged parallel with the longitudinal axis of the channel, one side wall of each laterally offset part of the channel having a concave face partially surrounding the comminutor and terminating at the transverse cutting axis thereof.

- AUGUSTUS C. DURDIN, Jx. 

